Multicathode ray discharge device



Aug- 29, 1939. M. s. GLAss Er AL 2,170,944

MULTICATHODE RAY DISCHARGE DEVICE AT TORNEV Aug. 29, 1939. M. s. GLAss 'Er AL MULTICATHODE RAY DISCHARGE DEVICE 2 Sheets-Sheet 2 Filed May 29, 1957 4/ 22 FIG 7 42 4'/ 22 A T TOR/VE V atenteci ug. 2Q, 193

2,110,944 A MUL'rIca'rnonE mir nIsGE DEVICE Application May 2s, 1937, serial No. 145,432 2o claims. (ol. 25o-'150) This invention relates to multi-cathode ray discharge devices and more particularly to such de'- vices for reproducing different phases of electrical phenomena or for providing multiple scanning beams for television purposes.

In the operation of cathode ray devices of the multi-unit type, it is advantageous to coordinate the cathode streams on the screen or other reproducing surface without distortion so that various aspects of the same or diiierent phenomena may be accurately interpreted. In order to se'- cure such distortionless operation it is essential to segregate the respective units and shield the individual streams against interaction in their travel to the rscreen which might influence the eiect produced on the screen.

An object of this invention is to assemble the multi-unit system of a cathode ray discharge device in such a manner that distortion eiects are substantially eliminated.

Another object of the invention is to fabricate the multi-unit system of such a device as a compact unitary structure so that it is rigidly maintained in position in the device.

In accordance with this invention a plurality of electron gun units are consolidated into a rigid unitary structure supported from a stem and are provided with a common accelerating electrode which sets up a uniform and identical field for each stream of electrons projected toward the screen of the device. The accelerating electrode also serves as a supporting base for a deiiector plate unit for each gun unit to insure symmetrical alignment of the plates with respect to the gun units. The several sets of plates are electrically independent, in so far as they aiect the adjacent electronic streams, since, in accordance with this invention, shields are interposed between the adjacent sets to avoid distortion of the streams or ineiiicient control in each deector plate unit.

A feature of the invention relates to the rigid alignment of the several electron producing gun units as a consolidated assembly to insure that the beams will be in paraxial relation toward the screen on the end of the device. This is accomplished by joining the units together by connecting members which are attached to supports extending from a stem of the tube. This arrangement overcomes mechanical strains on the various conductors extending through the press of the stem which supply the voltages to the aggregation of elements comprising the plurality of velectron gun assemblies and also avoids misalignment of the units due to mechanical stresses.

Another feature of the invention relates to the construction ofthe accelerating electrode assembly to insure eicient and collateral acceleration of the electron beams emerging from the electron guns. This assembly comprises a common metallic member having apertures corresponding to and aligned with the anodes of the electron gun units, which is secured to a tubular member supported on an extension of the vessel concentric with the stem and exterior wall of the device. This arrangement insures an accelerating eld of equal magnitude for all the streams of electrons being projected toward the screen of the device and increases the eiciency of transmission by providing a eld of uniform strength by virtue of the shielding eiiect of the tubular member.

A further feature relates to the rigid and compact assembly of the deector plate unit and comprises a supporting member superimposed on the common accelerating member, which is provided with slots to receive the different pairs of transverse deflector plates to maintain them in unifc rm and cooperative relation to the electron passages in the accelerating electrode assembly. The main dei'lector plates depend from the supporting member, while the 'sweep or time-axis plates eX- 'tend above the supporting member. The latter plates are accurately aligned in coplanar relation by connecting bars which are interlocked with transverse shielding plates located intermediate adjacent sets of sweep plates. These shields dene the boundaries between the different streams Aprojected toward the screen and avoid interaction between the streams in the vicinity of the deecting electrodes where distortion is apt to occur. The interlocking arrangement of the plates insures a rigid and stable assembly which overcomes distortion caused by mechanical variations in spacing of the plates.

These and other features of the invention will be more clearly understood from the following description when considered with the accompanying drawings:

Fig. 1 represents a complete embodiment of the invention with different portions of the glass vessel broken away to show the internal assembly and relation of the multi-cathode stream electrode unit;

Fig. 2 is an enlarged perspective view of the electrode unit of this invention showing the detail assembly with respect to the portions of the vessel which are shown in broken lines in order to more clearly illustrate the structural elements of the assembly;

Fig. 3 is an enlarged perspective view of the deector plate assembly, shown partly in exploded fashion, to illustrate the detail components of the assembly;

Fig. 4 is a plan view of the position of the electrode assembly in the vessel andthe various conductcrs of the electrodes and represents a view takcnonthelinel-lofll'lgnl;

Flg.5'isaplanviewoftheterminalsonthe vhasesoi'thedeviceshowninll'lg.linwhichthe outer terminals accommodate the lconductors shown in Rig. 4;

A Fig. 6 is an enlarged view in elevation showing, partly in section, the gun assembly and the accelerating electrode.

Flg.7isaplan view of themounting of the gun ase'smblytakenontheline'I-loflilgand showing the connections to certain elements thereof;and y' l'lg.8shows inelevationthedetail structure ofaportionofoneofthegununitsoflllg.6.

Referringtoizhedrawingsandlllgs.1and2 Jection portion il which terminates in a large diameter dome portion l2 and an extension portion Il forming a continuation of the body portion Il. The cylindrical portion IlV and the conical portion Il are provided with an interior coating Il, preferably of a conductive substance, such las graphite, which is applied to the walls of the tube as a Ycolloidal mixture and dried thereon. 'Ihe dome portion of the vessel I2 is provided with a nuorescent coating Il, such as willemite. calcium tungstate, zinc silicate, or mixtures thereof, or any other suitable fluorescent substance or composition. The extreme end of the tubular extension Il is provided with a reentrant stem Il and also provided with a coextensive but longer inner tubular wall i1 which is joined to the extension il at thepoint Il and extends into the tubular portion il of the Y enclosing vessel. 'Ihe tubular wall Il and the stem Il provide an axial chamber at one end of the device for mounting the electron gun unit of this invention so that the multiple beams or streams therefrom are projected in paraxial relation toward the screen Il on the opposite end of the device.

InFig. 21s shownthreeparallel gununits Il, 2l and 2i. Each unit comprises aplatform 22 in the center of which is mounted a cylindrical heater type cathode 23 surrounded by a cupshaped modulating or control electrode 24, as shown in Fig. 8, which is surrounded by an elongated tubular anode or focusing electrode 2l having an internal collimating element 26 spaced from the control electrode. as shown in Fig. 6. 'I'he anode 2i and the collimating element 2l have ways that are coaxially aligned with an aperture in the control electrode 2l by the integral convex abutment Il on the platform 22. 'l'hese combined elements on the platform 22 form the electron gun unit and each unit is identical in structure. 'Ihe dimensional configuraspacing and. functional operation of the electron gun unit above described is more clearly The consolidated ing-in points lset forth in U. S. Patent 2,139,878, issued December 13, 1938. to M. S. Glass.

'Ihe three gun units are led as a consolidated structure by Joining them together with transverse connecting members 2B, 29, J0 and Il having inner ilange portions 32 welded to points on the cylindrical surfaces of the anodes of the guns, a shelf portion 33 extending outwardly from the inner'ilange and an outer iiange portion Il extending parallel with the inner flange, but in a reverse directionv The connecting members are attached to the glm units in pairs on opposite diametrical points of the anodes withtheupperpairhavingtheouteriiangextending in parallel relation toward theterminations of the gun umts, while the lower pair have the outer ilange portion extending downwardly toward the platform 22 ofthe gun units.

in -paraxial relation to the axisofthechamber. Thisrelationshipis insured by a rigid supporting structure involving four straight rods II which extend in parallel relation from two collars 3l and Il embracing the stem I0, the rods projecting through the sheli portions 33 of the connecting members and being welded to the iiange portions thereof. The difference in diameters between the gununitsandtlie stemiscompensatedbythe wide lshelf portions ofthe connecting members so that the units are under no mechanical strains which might ailect their paraxial relationship with respect lto the chamber axis. Purthermore, the stem arrangement for supporting the gun assembly overcomes the necessity of `re-.

lying on the leading-in conductors of the various units for supporting the assembly and, therefore, these conductors are relieved of stresses which might cause fracture at the sealthereof, cr cause a slight change in space relation of the electrodes to which they are attached. v

'I'he various electrodes tached to the leading-in conductors of the tube, as shown in Pigs. 2, 7 and 8, collectively, in which the heater elements of the cathode 2l may be connected in parallel or in series. as shown in Fig. 7, and joined to conductors 8l and which are sealed in the arms of a press ,formedvon the inwardly extending stem Il. The cathodes 23 are connected to short extensions kIl which may be Joined by a wire strap I2 and connected in parallel to a conductor Il `which extends through the press 4l. If desirable the cathodes may be connected in parallel relation. 'Ihe control electrodes 24 are connected tov stub wires M and these wires are connected to separate leading-in conductors .18 and", respectively, which are also sealed in the press Il. All the conductors extend through the stem and are Joined to terminal pins Il on a base 4l cemented to the end of the tubular extension Il of the enclosing vessel. A leading-in conductor Il in the press 40 is connected by a strap tovone of the straight rods and since these rods are electrically connected with the anode 2l of each gun unit, a suitablepotential may be applied thereto through this conductor. The terminals 4l on the base 49 are shownin Fig. 5 and arranged in a counterclockwise direction with designations corresponding to the various electrodes so that the leading-in conductors passing through the stem I6 do not cross one another and thereby cause difficulty in the operation of the device. The common anode terminal A is connected to the leading-in conductor 50, G1 is connected to conductor 45, H is connected to one of the heater conductors 38, G2 is connected to the conductor 46, Gf.; is connected to conductor 41, H is connected to the other. conductor 38 of the heater elements and C is connected to the common cathode conductor 43.

The chamber in which the gun units are located is provided with a closure member or disc 5I having three apertures 52 having the same diameter. The apertures are coincident with the hollow openings of the gun units I9, 20 and 2I. This closure member is secured to the chamber wall I1 by a metallic sleeve 53 which is hermetically sealed to the glass by a knife edge seal 54. The closure member 5| is placed adjacent the exit of the electron guns to serve as an accelerating electrode and increase the velocity of the electron beams passing through it. In order to accelerate the electron beams passing through the disc 5I, a suitable high positive potential is applied thereto and since this potential is also applied to the shield or sleeve member 53, it has been found that when the disc 5I is widely spaced with respect to the ends of the electron gun units, diiculty is experienced with the electron beams in the end units I9 and 2|, due to the attracting eld of the shield 53. This causes considerable distortion of the paths and of the focus of the beams in the end units. This difiiculty can be avoided by inserting a metallic mass or other lengthening member 55 between the disc 5I and the ends of the electron gun units, the mass having passageways corresponding to the apertures 52 in the accelerating disc electrode 5I and the ends of the anodes of the gun units. This arrangement provides uniform and identical eld relations for the three gun units so that the electron beams emanating from the guns extend in paraxial relation through the mass 55 and the accelerating electrode 5I.

While this arrangement is satisfactory in the construction shown, the mass is not essential in the embodiment of the invention since the same effect may be secured by extending the tubular members of the gun units up to a position near the accelerating disc 5I, but retaining the short space relation between the gun units and the disc 5I in the same manner as shown in Fig. 6, in which the space relationship is shown between the gun units and the end of the mass 55. The assembly of the gun units and the common accelerating electrode in combination with the chamber wherein the electron beams are originated provide an organization in which the rigidity of the electrode elements is assured and the protected arrangement of the gun units in the chamber insures parallel beams of high intensity and efficiency so that all phases of electrical phenomena depicted on the screen I5 will be of equal intensity so th'at the indications will have a high actinic value and accurate recording may be made of the complex figures produced thereon.

While the multi-unit assembly may find application in a large eld such as television, electromedical investigation and in aircraft for radio beam indicators, there is also a large field of use for service equipment and laboratory measurement in which it is desirable to sweep the various beams over the whole area of the iiuorescent screen simultaneously to reproduce different phases of electrical phenomena. In the latter field it is essential to provide deecting elements, preferably in the device, and the prevalent custom is to produce this deection by electrostatic inuence. This is produced most eiliciently by suitable deector plates arranged laterally with respect to the electron beams projected toward the screen of the device.

In accordance with this invention, all the electron beams are electrostatically controlled by a deflector plate unit which is rigidly mounted beyond the accelerating electrode 5I and is secured to the disc in such a manner that a compact and rigidly assembled structure is provided. Furthermore, this assembly also includes separating` shields between adjacent sets of deector plates to prevent distortion of adjacent beams, yet at the same time permitting the beams to sweep the complete area of the screen at the end of the vessel.

This is accomplished in accordance with this invention by mounting an insulating platform 56 above the accelerating disc electrode 5I and connecting the platform to the disc by posts 51 arranged at diametrical points. The platform 56 is provided with three apertures corresponding to the apertures 52 in the accelerating electrode 5I and the gun units I9, 20 and 2l, and a plurality of bisecting slots on opposite surfaces to form guides for the various sets of plates attached to the platform. Reference is made to Fig. 3 in describing the assembly of the deilector plate unit in which the main deiiector plates are shown depending from the platform 56 while the sweep or time-axis plates are shown extending above the platform. This relationship is not essential in the operation of the device since the same eiect may be secured b-y reversing the positions of the plates with respect to the gun units. All the depending deector plates are of the same construction except that they are arranged in different sets, but all in parallel relation. Plates 58 and 59 are provided with end extensions 60 and 6I which extend through end slots 62 and a longitudinal slot on the bottom surface of the platform 56 to rigidly position the plates with respect to the aperture 63 in the platform, the ends of the extensions being bent over as shown at 64. Plates 65 and 66 are arranged adjacent the center aperture in the platform and similarly attached to the platform while the plates 61 and 68 are arranged adjacent the third aperture in the platform and have their extensions bent over the top of the platform in a direction opposite to that of plates 58 and 59. The slots in the platform and the extensions on the plates insure rigid positioning of the plates and uniform parallel relation with respect to the axis passing through each aperture 63 in the platform.

The sweep or time-axis plates projecting above the platform are mounted in a slightly diierent manner from the lower plates to insure a rigid construction and avoid conduction between the Various sets of plates. The end plates 69, 10, 1I and 12 are of similar construction, but are arranged in parallel coplanar relation above the platform 56 in transverse position with respect to the lower corresponding sets of plates. These plates are provided with extensions 13 and 14 which t into end slots 15 in the platform 56 while the lower edges of the plates t in slots which are formed across'the outer boundary of the aperture 63, the ends of the extensions being bent over on the lower surface of the platform to rigidly secure the plates in position. 'I'hese plates are also provided with channel extensions' 10 and 11 on the outer surfaces thereof to engage portions of a pair of locking bars 18 and 19, of insulating material, which are lprovided with undercut portions corresponding to the length of the channel extensions 16 and 11. The center plates 80 and 8| are not provided with extensions similar to the end plates 89 and 12, inclusive, since these extensions wouldl make contact with the lower center plates 05 and 88. Therefore, the center plates are supported in parallel relation by being interconnected with the end platesk by channel extensions 82 and 88, which embrace the locking bars 18 and 19. The lower edges of the plates 80 and 0| are arranged in guiding slots on opposite sides of the center aperture. It is evident that these plates are thus rigidly secured to the platform 56. The upper plate assemblies are further strengthened by shielding plates 84 and 85 whichare arranged between adjacent parts of upper deilector plates and are provided with extensions 80 and 81 which register with-side slots in the platform 56 and are locked in position at their lower ends by bending over the ends of the extensions on the lower surface of the platform. The shielding plates are further provided with undercut portions which register with slots 88 and 89 in the locking bars to insure constant spacing between the coplanar sweep plates and also to provide a compact interlocking arrangement of the various sets of plates and shields without endangering the individual sets of plates and at the same time avoid distortion between adjacent electron beams projected through the various sets of plates. This arrangement insures a rigid and compact assembly in which the various plates are maintained in their proper spacial relation with respect to each other and with respect to the electron streams passing between them. Furthermore, the'rigid assembly of the deilector plate unit from the rigid chamber structure of the tube insuresaccurate alignment of the deilector plates with respect to the` gun units mounted within the chamber.

Each of the defiector plates is provided with a terminal conductor in order to apply appropriate potentials to the diierent sets of plates to iniiuence the electron beams passing through the passageways formed thereby. In order to cor' relate the conductors leading to the various deilector plates, vsaid plates are designated as sets, i.- e., plates 50 and 59 being designated the lower plates of A set. while plates 09 and 10 are the' upper'plates of A set, the similar plates of the center set beingthe B set, while the last plates 51, 08, 1| and 12 constitute the C set. With these designations it is believed that the connections of the appropriate terminals-90, shown on a base 9|, in Fig. l, to the deflector plate conductors can be followed more clearly fromv the following description. Fig. 5 shows the terminals 90 in positive relation with respect to the radial conductors of the deflector plates shown in Fig. 4.

The terminals shown on base 9| in Fig, 5 are provided for the twelve individual deflector plates mounted in the vessel and also for the application of a suitable potential to the accelerating electrode 5| and the conductive coating |4 on the interior wall of the cylindrical and conical portions and respectively, of the vessel. These terminals are connected to the various elements in the following manner, the ,description progresing in` a counter-clockwlseg/direction beginning with terminal G. This ter/minal is connected to conductor 92 which is sealed at one endthrough the wall of the vessel and connected to one of the posts 51 by a strap 83. This conductor is also connected to the shield plates 84 and 85 by additional straps 94 and 95. The posts 51 supporting the defiector plate unitv are also provided with curved springs 80 and 91 which engage the graphite coating I4 on the interior wall of the vessel. In this arrangement the accelerating electrode and the conductive coating I4 may be supplied with a high positive potential to accelerate the electrons in the beams passing through the various units and at the same time a ground connection may be connected to this terminal in order that the shields 8 4 and 85 may be grounded and to avoid the effect of a large difference of potential i v nected to conductor |02 which is joined by a strap |08 to the first upper plate 1| of the C set of plates, while terminal UC: is connected to conductor |04 having a strap |05 connected to the upper second plate 12 of the C set of plates. Terminal LCn is connected to conductor |06 which is joined to a strap |01 connected to the second lower plate 68 of the C set of plates and terminals LBz and LB1 are connected to conductors |08 and |09 which are joined by straps ||0 and to the lower plates 06 and 65,- respectively, of the B.set of plates. Terminal LA1 is connected to conductor I2 which is attached to a strap ||3 joined to the rst lower plate 50'of the A" set of plates. Terminal UBz is connected to conductor ||4 which carries a strap ||5 joined to the upper second plate 8| of the B" set of plates. Terminal UAz is connected to conductor IIS having a/strap 1 connectedl to the second upper plate 10 of the A set of plates, terminal UA1 is connected to conductor ||8 having a strap ||9 attached to the first upper plate 69 of the A set of plates, and terminal LA: is connected to conductor having *a strap |2| attached to the second lower plate 59 of the A set of plates. This larrangement insures adequate insulation resistance between all the various conductors for the deilector plates and provides a separate terminal for applying suitable potentials to the various deilector plates either in combination or individually to influence the various electron beams passing between the plates.

While the device herein described may contain all the features enumerated, it is to be understood that the invention is not limited to such a specific combinationgsince under certain operating conditionscertain'features may be omitted without departing `from the scope of the invention. For instance, in television devices the screen may be omitted if the invention is to be employed as a. multiple beam device. Similarly, in other fields of operation the deflector plates may be omitted. Therefore, in accordance with this invention it is to be understood that the disclosure is only to be limited within the scope of the appended claims.

What is claimed is:

1. A multi-beam projection device comprising an enclosing vessel having a cylindrical reentrant' portion forming an internal chamber, a plurality 75 of beam producing units arranged in parallel relation in said chamber, a metallic electrode common to all said beam producing units in cooperative relation to said chamber and said units, sets of deector plates arranged in transverse pairs individual to each beam producing unit, and means supporting said sets of plates from said metallic electrode.

2. A multi-beam projection device comprising an enclosing vessel having a cylindrical reentrant portion forming an internal chamber, a plurality of beam producing units arranged in parallel relation in said chamber, a metallic electrode common to all said beam producing units in cooperative relation thereto, sets of plates arranged in transverse pairs individual to each beam producing unit, a support for said plates carried by said metallic electrode, and shielding means between the aligned edges of adjacent sets of said plates.

3. A multi-beam projection device comprising an enclosing vessel having a cylindrical reentrant portion forming an internal chamber, a plurality of beam producing units arranged in parallel relation in said chamber, a metallic electrode common to all of said beam producing units in cooperative relation thereto, and a tubular shielding extension superimposed on said reentrant portion and forming a support for said metallic electrode.

4. A multi-beam projection device comprising an enclosing vessel having a cylindrical reentrant portion forming an internal chamber adjacent one end of said vessel, a plurality of beam producing units arranged in parallel relation in said chamber for projecting colateral beams toward the opposite end of said vessel, a set of deilector plates adjacent each corresponding unit, and means supported by said reentrant portion and interposed between said units and defiector plates and closely spaced with respect to said units to provide uniform concentrated eld relations for the colateral beams emerging from said units.

5. A multi-beam projection device comprising an enclosing vessel having a cylindrical reentrant portion forming an internal chamber adjacent one end of said vessel, a plurality of beam producing units arranged in parallel relation within said chamber for projecting colateral beams toward the other end of said vessel, a set of deiiector plates adjacent each corresponding unit, and a common surrounding electrode mounted on an end of said chamber and separating said units from said sets of plates.

6. A multi-beam projection device comprising an enclosing Vessel, a plurality of beam producing units arranged in parallel relation at one end of said vessel lor projecting colateral beams toward the other end thereof, a set of deflector plates adjacent each corresponding unit, an electrode common to said units surrounding the upper ends thereof and separating said units from said sets of plates, and a metallic mass secured to the common electrode and having apertures in alignment with said units.

7. AV multi-beam projection device comprising a vessel having a reentrant insulating chamber portion and a projection portion, a metallic closure member attached to said chamber por tion having a plurality of apertures, and a plurality of electron gun units in said chamber corresponding to the apertures in said closure member, said units being aligned with said apertures for projecting simultaneous beams of ele@- trons through said projection portion,

8. A multi-beam projection device comprising a vessel having a reentrant insulating chamber portion and a projection portion, a metallic sleeve member sealed to said chamber portion, a metallic closure member engaging said sleeve member and having a plurality of parallel openings tiierein,. and a plurality of parallel electron gun units nsaid chamber aligned with said openings, said units projecting within the limits of said sleeve member.

9. A multi-beam projection device comprising a vessel having a reentrant insulating chamber portion and a projection portion, a metallic sleeve member carried by said lchamber portion, a metallic closure member engaging said sleeve member and having a plurality of parallel open-f ings therein, a plurality of parallel electron gun units in said chamber aligned with said openings, and sets of deflector plates corresponding to said openings adjacent thereto and supported by Ysaid chamber portion, said gun units being isolated from said sets of deector plates except through said openings in said closure member.

10. In a multi-beam projection device a vessel having a reentrant insulating chamber portion, a stem projecting therein, a plurality of electron gun units in said chamber arranged in parallel relation to the axis of said stem and chamber, straight spaced supporting rods extending from said stern, metallic strap members connected to said units and rods, said members compensating the difference in diameters between said units and said stem, and a metallic closure member mounted on the end of said insulating chamber portion, said closure member having openings aligned with the units in said chamber.

1l. In a multi-beam projection device, an enclosing vessel having a chamber portion, a stem therein, a plurality of coextensive electron gun units positioned beyond said stem in said chamber, a collar on said stem, rigid supports extending from said collar parallel to said Units` flanged connecting straps joined to said units and having a shelf portion extending outwardly for engagement with said supports, a metallic sleeve sealed to said chamber portion, and a disc member secured to said sleeve having passageways aligned with the units within said chamber portion.

12. A multi-cathode ray discharge device comprising a vessel having a fluorescent screen at one end, a plurality of parallel electron gun units directed toward said screen and supported in the opposite end of said vessel, a tubular member surrounding said gun units, an accelerating electrode forming a closure for said tubular member and having apertures aligned with said units, an insulating member spaced beyond said accelerating electrode and supported thereby, said insulating member having apertures corresponding to the apertures in said electrode, a plurality of sets of dei-lector plates extending below said insulating member, a like number of deflector plates j' extending above said member, said plates forming separating passageways in line with the apertures in said insulating member and accelerating electrode, and a shield plate between adjacent pairs of deflector plates.

13. A multi-cathode ray discharge device comprising a vessel having a uorescent screen at one end, a plurality of electron projection systems mounted at the other end, each system including an electron gun unit and a set of deflector plates, an enclosing chamber for the gun units, and a mounting for all the deflector plates supported by said chamber, said mounting comprising an v sets of defiector-plates in relative positions 'forv Acontrolling the direction of the separate streams' said gun units and slots adjacent said openings on opposite sides of said plate for supporting said Aof electrons projected toward said screen.

14. In a multi-beam projection device, an elec-` trode assembly including three electron gun unit's arranged in parallel relation, and anassociate unit of deector plates for said gun umts, said associate unit comprising an vinsulating supportI having openings corresponding/tol said gun units,

va pair of deector .plates adjacent eachopening and extending downwardlyl from said support, a second pair of deilector plates extending from Athe opposite side of said supportadjacent each opening, extensions on the end pairs of-saidv latter f plates to secure them to said support,'and a con@v nector extending lbetween-the end'v plates, said connector v being secured toy the' intermediatede ector plate to prevent displacement thereof.,4 l y 15. In a multi-beam projection device, an-elec trode assembly including three electron gun arranged in vparallel relation, and an associate;- unit of deector'plates for said gun units,"said associate unit comprising an insulating support having openings corresponding to said gun units,

a pair of lower deiiector plates adjacent-each opening in said support, a pair of upper vdeilector-` -plates extending from said support adjacent each' opening, extensions on the end pairs of said latter plates to secure them to said support, channel extensions on the free ends o1' said upper plates, an insulating rod extending through said chan-A nel extensions, and transverse shielding 'platefs interposed between each pair of upper plates and engaging said support and said insulating rod in interlocking relation to form a rigid unit.

16.v An electronic discharge device of the multibeam type comprising an enclosing vessel having a plurality of electron gun'units, a iluorescent screen adapted' to indicate simultaneoustraces of all the electron beams projected bysaid a. metallic disc member having apertures therein corresponding to the'number of units within said vessel and'y separating said units from said screen whereby said beams can only reach said screen through said apertures, a deilector plate mounting between said disc andv said screen, said mounting including a. platform andindividual/,setsy of opposite side of said relation,y and metallic shields assembly, l 1 18. -A multi-beam projection device comprising openings'individual to each y s470344.y insulating plate having openings aligned-'withl detlector plates for each gununit; certain plates oi'each setbeing arranged in parallel relation said disc and said platandsupported between form, andthe remaining defiector plates being arrangedtransverse to the other plates on the platform in pafied coplanar pairs ot-coplanar defiector plates.

a vessel liavinga reentrant chamber therein, a

pluralityoi beam producing units therein, an

apertured electrode forming a closure for said chamber, a plurality of sets of deectorvplates mountedy on said electrode, shields between adjacent sets of said plates, and interlocking means connecting said'plates and shields into a rigid la veel havingla fluorescent coating on one end and/a reentrant chamber at the other end, a

t, plurality orbealn producing units within said y chamber, and a metallic electrode substantially closing said chamber and forming'a barrier between said umts Vandl said screen except through unit. l19. A multi-beam projection device comprising "a vessel having auorescent coating on one end -land a reentrant chamber at the other end, a plurality oi' beam producing units within said chamber, ametallic electrode substantially closin g said chamber vand forming a barrier between said unitsand said screen except through openings individual 'to each unit, sets of.v deflector plates for each 'of said units mounted on said electrode, and conductors for said plates and said electrode lextending longitudinally between said chamber and-the wall of saidvessel. l t

. 20. vA multi-beam projection device comprising avessel having an internal reentrantcylindrical chamber, a stem therein, a metallic disc electrode supported on the edge of said chamber and sub.

. stantially closinggthe same,y saiddisc-having a,

row of apertures thereim a plurality of-electron gun units within said chamber, and a metalliciframe yprojection vfrom said stem and mounting saidv units in aligned relation to therow of apertures fin .said `,disc electrode.

MYRoNgs. GLASS. l f DOUGLAS A. s,HALE.

between adjacent t 't A 17.A lmulti-beam projection device comprising 

